The geolocation of signals from high altitudes is increasingly vital to combat terrorism and support war fighting globally. In a recent paper [1], the author described an approach to improve geolocation performance by focusing on understanding the impact of biases, particularly navigation errors, on sensor platforms. That analysis model used a hypothetical scenario with drones collecting time and frequency data from an emitter at an altitude of 10 to 15 km for several minutes, with a strong, time-varying observation geometry. This note applies that model to a case of more practical interest: shorter observations (a minute or less) from geosynchronous altitudes and a fixed observation geometry over a very large coverage area. The considered covariance approach, with the use of the full 6x6 navigation error in the covariance computation, is shown to be a valuable tool in the system engineering specification of the collection system, as well as in addressing biases and improving system geolocation performance.
